1. Field of the Invention
The invention relates generally to a water system for first condensing water vapor from the atmosphere, subsequently collecting the condensate to supply freshwater, treating the freshwater and dispensing potable water in areas suffering from shortages of freshwater wherein the climate is characterized by extended periods of extremely high temperature and very high humidity.
2. Summary of the Invention
Freshwater is needed everywhere at all times for sustenance of any form of life on earth. Potable water is necessary for survival of human kind. Continuous supply of freshwater is required for other vital uses in daily life such as irrigation and cultivation of land, drinking of domesticated animals and birds, cleaning, washing, and preparation of foods and drinks. This is in addition to the role of fresh water in driving the wheels of industry and generation of electricity. While several forms of natural freshwater resources are available, they are limited and not readily within reach for direct use of people everywhere. In fact, disputes over water rights and wars for rights to access freshwater are expected to escalate in the near future.
In the past, people searched for locations to settle wherever freshwater sources were conveniently accessible, nearby rivers or lakes, and around locations of abundant groundwater or within regions of sufficient rainfall. Whenever water resources dwindled or became scarce, they moved on to develop new settlements where they had easy access to ample supply of water. As the earth became heavily populated, fertile and water-rich land became overcrowded and eventually communities had to settle in regions of limited water resources. Furthermore, change in weather patterns has reduced rainfall in some areas and deserts started to creep in as water resources were depleted, while the inhabitants had no recourse but to stay.
Accordingly, means are needed to supply water from available water resources that may not be readily accessible. Examples are transportation of potable water sources located further away from population centers; tapping in sources of water that require little to extensive treatment before use for human consumption; and employment of proven technologies to produce freshwater from raw water, such as salty or contaminated groundwater, high salinity seawater, or contaminated water from rivers or lakes.
People have long relied upon underground water as a source of continuous water supply, however, increases in industrial and agriculture activities have led to its rapid depletion as well as contamination of that valuable water resource. Rivers and lakes are not capable of meeting local demand on water in some regions and are polluted in other regions. Furthermore, the inevitable shift in global weather patterns throughout time resulted in scarcity of water in populated areas that previously enjoyed plentiful supply of freshwater. In some areas people lost access to any local surface or ground water sources of water. Because of these shortages, vast areas of land are entirely deprived from natural freshwater resources, thus, water has to be transported across long distances and at very high prices, whether for the capital cost of the infrastructure or the extensive expenditure on land or sea transportation. This is compounded by the high potential of water contamination en route.
For areas along the shorelines of oceans or seas, or wherein brackish groundwater is available, water desalination has been used wherever feasible by means of flash desalination, reverse osmosis, electrodialysis, or ion exchange depending on the salinity level and the economics of different raw water treatment technologies and their future development. Furthermore, there are emerging technologies for treatment of polluted or contaminated underground water resources, rivers and lakes, however desalination and other treatment technologies are economically viable only at large production scales that require huge installations, complex distribution systems and a large customer base to exploit the economy of size. As a result, this limits the implementation of such approaches to securing the water supply to large population centers wherein the demand on water is increasing and the consumption is already high.
Generally, natural freshwater resources are limited in regions along the shorelines and within the vicinity of large salty water bodies that are characterized by extremes of high temperature and high humidity throughout the year. Such regions often have low precipitation year around and groundwater is also limited due to lack of rainfall to replenish the water resources, difficulty to grow plants and trees that aid in precipitation of atmospheric water, and absence of forests that contribute to the natural water supply from fog. The fast rate of consumption of underground water leads to depletion of the water stored in the natural aquifers and to a lowering of the water table associated with an increase in the salinity of groundwater. Agricultural and industrial activities, even at a large distance from the site where freshwater is scarce, have led to contamination of underground water everywhere through their emission of insecticides, herbicides and a host of other toxic chemicals.
Water economy strategies may reduce the water demand but any water conservation measures will not be sufficient to supply areas deprived of any type of water resources. Potential reuse of wastewater after treatment may supply a portion of the water demand, although in some situations the cost of processing, filtration and purification may be prohibitive.
In spite of the vast progress in water treatment technology and the ability to supply people with freshwater anywhere at any time, there are situations in which it is practically impossible to economically provide some population centers with freshwater in a manner compatible with local water demand and daily needs. Vivid examples of the difficulty to access good quality drinking water are numerous. Inhabitants of population pockets in the African deserts are forced to drink water with high salt content and harsh taste. Bedouins suffer from scarcity of water for drinking and for raising their sheep. Dwellers of rural regions, remotely located settlements and scattered low population areas have great difficulty accessing a reasonable supply of freshwater for drinking to maintain there health and well being and to sustain the sparse agriculture activities that provide them with food supply.
Accordingly, there is an urgent need in the art for simple and low cost water systems to supply freshwater to sparse population centers in remote areas that are isolated from metropolitan regions; especially those population pockets that have no access to municipalities or the main supply of water for large cities. These water systems should be easy to operate and require minimal or no maintenance. Since most of the potential users have no access to any central electric power services, electric power requirements should be limited and are preferably delivered by small mobile electric power generators that do not require a connection to electrical power grids or a supply of local electricity.
With the continuous development of water desalination and water treatment technology, relatively small units have been designed and manufactured to supply potable water for limited groups; such as the skid mounted and truck-mounted reverse osmosis (RO) units currently employed by the U.S. Military. However, such units are costly in maintenance, require frequent replacements of RO membranes, consume large quantities of electric power and are subject to frequent outages and repairs. Furthermore, the addition of pretreatment chemicals is necessary and plant design and production require information on the composition of the raw feed water, including salinity and presence of minerals and contaminants. Also, small distillation systems are often used in homes to produce pure potable water from tap water. However, these units as well as other small filtration units require a relatively clean water source. All of the small water treatment units require access to raw water resources.
Accordingly, there is a need in the art for simple and small, low cost, minimal maintenance, easy to operate devices for supplying drinking water sufficient for a small group of people when raw water supply is not readily available due to high salinity or contaminated water resources.
Water resources are not limited to rainfall, snow, underground aquifers or surface water. Atmospheric moisture is an alternative renewable water resource. The water density in the air or the absolute humidity near the surface of the earth ranges between four (4) and twenty-five (25) grams of water per cubic meter of air. While humidity of the ambient air in crowded and populated area can reach up to ten (10) grams of water per cubic meter of air, the absolute humidity in regions located near ocean and sea shores often reach the upper limit of twenty-five (25) grams of water per cubic meter of air.
In reality, ambient air in any habitat, even in areas of relatively dry air, contains an appreciable amount of water vapor since human, animals, birds, plants and all other living beings require the presence of atmospheric moisture to survive. All living cells contain a high percentage of water. As the ambient temperature rises, the flow of dry air evaporates water from the earth surface until concentration is reached. In hot and arid climates, evaporative cooling is the only method of cooling humans and animals When surface water is not available, water is evaporated from plants and living cells, leading to dryness and dehydration of the cells and inevitable loss of life. Unless replenished by drinking water or other fluids, the loss of body moisture is the prime cause of fatal dehydration in dry regions and deserts. On the other hand, people in humid regions are not subject to the same risk when the water is scarce. The same situation applies to all living beings. Evaporation of water from the skin of humans and vapor release from daily activities of cooking and boiling of water results in a rise of humidity in closed spaces and crowded areas.
Atmospheric moisture is an excellent natural source of water regardless of the amount of water vapor content of the air. The lower layer of the atmosphere surrounding the earth contains over three trillion cubic meters (3xc3x971012 m3) of renewable water, which is about one-thousandth (0.001) of the water stored on the entire surface of the earth. By comparison, the daily drinking water consumption of the earth population is about two hundred twelve million cubic meters (2.12xc3x97108 m3), which is a very modest portion of the water entrapped in the atmosphere. Meaning, free atmospheric water that is accessible to all mankind on the earth can satisfy in abundance all of the drinking water needs anywhere and anytime. The atmospheric moisture reserve will not be depleted by excessive extraction of water since the water vapor is continuously replenished by evaporation of surface water and the surface of the mountains and valleys due to the flow of hot air.
Accordingly, there is a need in the art for innovative technologies for extraction of fresh water from ambient air moisture that can supply human needs, where conventional raw water resources do not exist.
High mobility and the rise in travel across deserts and arid lands, whether for military operations, business, or the transport of goods, are associated with complications of access to potable water supply and running the risk of dehydration from unanticipated shortage of water, or the use of water sources that cannot be trusted. Although aboard land vehicles are capable of transporting water tanks that contain sufficient provisions of potable water, they can be inconvenient and would require an accurate estimation of the quantity of the water required for the trip. In addition, heavy water-filled tanks will increase the overall cargo weight of a large caravan.
Accordingly, there is a need in the art for a small mobile water system for supplying drinking water to a small group of people whenever necessary and without the need for ground or surface raw water resources. There is also a need for a small mobile water-producing system for use in land transportation vehicles, and hence, can be mounted on trucks, trailers or passenger vehicles without adding burdensome weight or occupying an extraordinary large space inside the vehicles.
Additionally, continuous supplies of freshwater and potable water containers aboard seagoing vessels such as ships, boats and yachts require installation of relatively large freshwater storage tanks, huge systems for seawater desalination and/or wastewater treatment for recycling. The space occupied by water containers aboard seagoing vessels often reduces the space available for cargo or limits the efficient utilization of the space for other beneficial uses.
Accordingly, there is a need for a small mobile system for placement aboard seagoing vessels such as ships, boats and yachts that provides a continuous supply of drinking water.
Furthermore, many popular tourist areas and resorts located in/near arid regions or deserts near seashores often suffer from a shortage of clean drinking water due to minimal seasonal rainfall and brackish underground water. These resort areas are often overcrowded during the tourist season and under-populated otherwise, and hence the great disparity in demand for potable water makes the construction of seawater desalination plants or large water treatment plants a non-economical option. Moreover, the transport of freshwater for distribution in these areas is a costly option and exposes the water to contamination. The reliance of tourists on expensive bottled water represents a great financial burden on the tourists and does not provide for freshwater needs for other uses.
Accordingly, there is a need in the art for freshwater producing systems that supply cabins, cottages and tourism installations with fresh water throughout the tourist season in areas characterized by high temperature and high relative humidity.
Additionally, the water quality in many regions that depend on the supply of water through shipping by sea or land is often below drinking standards as a result of contamination during transportation, loading and/or unloading as well as during storage in local water tanks at the site of use. Using transported water may require minor treatment and protection during storage. This often forces the residents of these regions to resort to use expensive bottled water as a trusted drinking water supply source. However, the collection of atmospheric moisture would reduce the expenditure on water as one of the basic vital commodities in the market, and, depending upon the climatic conditions of the region, may also satisfy other uses of water other-than drinking.
Accordingly, there is a continuous need for relatively large water systems to supply a large population with high quality freshwater in areas deprived from any local sources of freshwater yet having abundant atmospheric water resources.
In addition, great gatherings of people, for example, festivals, pilgrimages, and other popular occasions, may last for short durations ranging from hours to a few days, but often require the shipment of freshwater and potable bottled water across vast distances since they are usually located in limited open areas that are often ill-equipped with plentiful supplies of freshwater. For example, the supply of freshwater to pilgrims during the Hajj season in Mecca is costly and problematic since its desert location is often occupied by more than 2 million peoples whom have little or no local water supply systems.
Accordingly, there is a need for relatively large water systems for supplying a large population for short periods with freshwater and potable water in regions characterized by year-round high temperatures and humidity in place of water transportation. In this situation, the water systems must be capable of extracting water from ambient air without the need for a central electric power supply system, addition of chemicals, or the need for spare parts or maintenance and must be easy to operate with no attendance.
Furthermore, in many emergency situations, especially those caused by natural disasters, water supply systems get contaminated or temporarily shut down for extended periods due to loss of electricity; for example during earthquakes, severe thunder storms, hurricanes, tornadoes, eruption of volcanoes, flashfloods, etc. In such cases, transport of sufficient loads of bottled water or water tanks may be hampered by the destruction of the infrastructure or denial of passage. This is while weather conditions in most of these emergencies are such that ambient air is saturated with moisture.
Accordingly, there is a need in the art for systems to supply drinking water and freshwater during emergencies. Such water systems need to be available upon demand and immediately operable under all weather conditions and should not be subject to accessibility to raw water resources or availability of commercial supply of water, chemicals or spare parts.
3. Description of the Prior Art
Prior art encompasses several inventions that utilize chemical adsorbents to dry atmospheric air or moisture-laden gases. The moisture is extracted as water for use whether as drinking water or fresh water after appropriate treatment. The adsorbent is regenerated and recycled for reuse. The use of adsorbents may be necessary in cases wherein insignificant amount of moisture are present in the atmosphere whereas in the case of extremely hot and humid environments the use of chemicals seems to be a nuisance and would require additional steps for extraction of water and regeneration of the chemicals.
In U.S. Pat. No. 5,846,296, a method is disclosed for recovering and/or purifying water that is absorbed from a humid atmosphere. The moisture from the air is adsorbed on a suitable medium in a defined space, whereupon by the application of heat the moisture is brought to a condenser where it passes into a liquid state and is collected in a suitable manner. In order to improve the efficiency of this method the defined, sealed space is opened for the adsorbing medium, for free access to air at nighttime and is closed during the hot daytime period. Condensed water is passed out through a collecting funnel and a channel to a collection container. A device is also described in the form of a housing with walls that can be opened and closed, in which an adsorbing medium is located. In the upper part of the housing there is provided a condenser. The condenser is equipped with a drop collector that is connected to an outlet pipe to a collection container.
U.S. Pat. No. 5,233,843 discloses a system for extracting moisture from ambient air that includes a desiccant pond for absorbing moisture from the air to produce a water-rich desiccant and a means for vaporizing the moisture in the water rich desiccant. The process encompasses mixing the vaporized moisture with ambient air to increase the dew point of the ambient air, condensing the vaporized moisture to form a potable water condensate and returning the water lean desiccant back to the desiccant pond.
In U.S. Pat. No. 4,726,817, ambient air is canalized and cooled in a free space delimited by a thermally insulated enclosure and a radiating heat exchanger of which the outer face is heat-absorbing and the inner face is heat-radiating. Air is then passed through a curtain of hygroscopic fibers where water vapor condensates into liquid water which is evacuated through a conduit and, once dried, air is heated by flowing at the inside of a radiator recovering thermal energy emitted by the face of the heat exchanger through a transparent thermally insulating volume. Dry air is then exhausted through a vent to the atmosphere. Since air circulates naturally, it is possible to recover, autonomously and without any other energy supply, water contained in vapor form in the atmosphere of the implantation site.
In U.S. Pat. No. 4,377,398, a solid matrix of microporous adsorbent is utilized to provide a barrier between two bodies of a gaseous mixture of which at least one constituent is a sorbable vapor. Appropriate application of heat at the opposing interfaces of the adsorbent barrier produces a partial pressure differential across the barrier. The adsorbent material is energized from a convenient heat source; for example, solar energy. The vapor pump of the invention may be used for environmental refrigeration and may be of the open or closed type. Other uses for the vapor pump are for producing a supply of pure water from low vapor content air or for drying air by removing the vapor content.
In U.S. Pat. No. 4,365,979, a water-producing device was designed for extracting water from moisture-laden ambient air. The device includes: (1) a circumferentially spaced chambers packed with an adsorbent for adsorbing moisture in the air, (2) a driving subsystem for bringing one or more of the chambers into and out of communication with a first and second desorbing section, (3) a subsystem for passing ambient air through the chambers not in communication with the desorbing section, whereby moisture from the ambient air is adsorbed on the adsorbent and subsequently removed from the adsorbent in each chamber as that chamber is brought into communication with the desorbing sections, (4) a recycling duct connecting the post-desorbing section to the predesorbing section to complete a desorption circuit, (5) a subsystem for circulating air through the circuit to remove water from the adsorbent, (6) a subsystem for heating the air in the circuit, and (7) a subsystem for removing water from the circuit. The ratio of the number of chambers in communication with the desorbing sections to the number of chambers receiving moisture-laden air can be varied according to the temperature and moisture content of the ambient air. Other versions of the device are disclosed in U.S. Pat. Nos. 4,344,778, 4,304,577, and 4,299,599, which include a component for adsorbing a moisture in the ambient air in an adsorbent for adsorption or absorption; component for desorbing the water as a steam by heating the adsorbent; component for evaporating a low quality water with a latent heat in the condensation of the desorbed steam; and component for condensing the steam obtained from the low quality water into the liquid water, whereby the water productivity is remarkably improved.
U.S. Pat. No. 4,285,702 teaches a method of recovering water from atmospheric air consisting of two phases: an adsorption phase, during which cool, humid air is transported through a water-adsorbent material for adsorption of water vapor and a desorption phase, during which warmer, drier air is transported through the adsorbent material for pickup of water from the adsorbent material. The desorption phase generates a first air stream in a closed-loop path through a heater for heating the first air stream and then to the adsorber material and back through the heater. Continuing this step for a predetermined time, generates a second air stream by diverting a portion of the first air stream for circulation from the adsorber material through a condenser for yielding water by condensation, and joining the second air stream to the first air stream after passage of the second air stream through the condenser, whereby the second air stream may be heated by the heater and passed through the adsorbent material. Other versions are provided in U.S. Pat. Nos. 4,197,713 and 4,185,969. This method and devices are suitable for cold weather with a trace of humidity.
A plant for the recovery of water from humid air is described in U.S. Pat. No. 4,219,341, in which at night, cool humid air is passed through an adsorbent medium layer which adsorbs water from the air and in which, by day, air heated by solar energy up to a temperature which is above the ambient temperature is passed first through this layer to absorb water from the layer and then is cooled down so that the water condenses. The daytime air, when entering the adsorbent layer, is heated by solar energy with a radiator which is preferably a black anodized aluminum web in which the adsorbent medium may be embedded and/or by the adsorbent medium layer which is colored black for better absorption of sun rays. By using reflectors, the solarization upon the adsorbent medium layer and/or the radiator may be intensified. An earlier version of the device was also described U.S. Pat. No. 4,146,372.
U.S. Pat. No. 4,163,373 disclosed a device for extracting moisture from a space. A refrigerator is provided with a continuous length of capillary material that extends via an opening in the refrigerator wall into contact with an evaporator in an enclosed evaporator space and with an externally disposed condenser. A hygroscopic liquid is contained in the continuous length of capillary material for absorption of moisture in the evaporator space and for elimination of moisture outside the refrigerator wall. The two ends of the continuous length of capillary material are arranged in liquid-transmitting contact with each other so that the hygroscopic liquid flows in a closed circuit.
The aforementioned inventions do not relate to the present invention since they are based on the use of adsorbents, desiccants and hygroscopic material, and mostly address low humidity climate conditions.
Prior art has also encompassed water extraction of freshwater from the atmosphere using processes that rely upon heat convection in large structures. For example, a water precipitator was designed in U.S. Pat. No. 4,892,570 to provide a water supply over an extended surface area of land in a high temperature region by condensing water on piping chilled by a refrigerant circulating within the piping. The water precipitator comprises a combination of a refrigeration system constructed from coils of metal piping connected at one end to a tank filled with Butane and connected at the other end to an empty tank for condensing hot air into water; a structure for capturing the hot air irrespective of wind direction and which relies on convection to move the hot air past the refrigeration system; air intake device consisting of a series of air intake flaps that are activated, to the open or closed position, solely by the dynamic pressure of the incoming air for permitting hot air to enter into the structure.
U.S. Pat. No. 4,080,186 describes a device to extract useful energy and fresh water from moist air, with an associated removal of pollutant particles entrained in the extracted water. The device comprises an enclosure with a tall stack and an extended base that has means for the creation and utilization of a contained tornado, which is powered by the energy release associated with the rapid condensation of water from the incoming moist air. This patent is based on atmospheric conditions that do not pertain to the present invention.
In another invention, U.S. Pat. No. 4,050,262 discloses a device for extracting water from the atmosphere that has a chamber or a pair of chambers connected to a compressor by a valve controlled in its operation in response to an operating condition in the chamber or chambers. A suction fan is connected to the chamber or chambers to move air through the chambers. A further valve is arranged in the respective inlet to the chamber or chambers to facilitate an expansion condition or effect in the respective chamber. Two chambers are used to operate in alternate fashion so that heat is supplied to one chamber while heat is being withdrawn from the other chamber and vice versa and both chambers are controlled in response to the respective operating condition. In a similar arrangement, U.S. Pat. No. 4,148,617 discloses a device for recovering water from ambient air having two chambers. In one chamber a pressurized air stream is heated and in the other chamber another pressurized air stream is cooled after which the two air streams are mixed resulting in condensation of the moisture contained in the air streams which is then collected and put to use.
In U.S. Pat. No. 3,777,456, water is extracted from the atmosphere by circulating a large volume of a solution of lithium chloride in water continuously over a packing, resulting in absorption of water. The solution is bled off and passed through a desalination plant, where product water is produced. Concentrated brine is returned to the circulating volume.
In U.S. Pat. No. 3,748,867 a device was designed to obtain fresh water from moisture containing air, using an elongated flexible tube with its upper end attached to a lighter-than-air balloon, preferably in the form of a non-rigid airship (blimp). The length of the tube is sufficiently great to extend from about ground level to a temperature zone having a climatic condition in which the temperature or moisture distribution of the atmosphere is sufficiently different from that at ground level. This permits, either, condensation of moisture as moisture-containing atmosphere conducted upwardly into the tube or introduction of seed crystals, such as silver iodide, into the atmosphere to cause precipitation. In the first case, the tube is preferably terminated at its lower end at an opening spaced a short distance above a large body of water, such as an ocean, and maintained on floats or pontoons located in the sub-tropical or tropical regions. Moisture-laden air from the ocean is drawn into the tube so that water only will condense on the tube walls, at the upper atmospheric reaches, to be drawn off and collected. In the second case, when seed crystals are to be introduced, the tube is preferably mounted on an automotive vehicle for wide dispersion of seed crystals.
A freshwater cooling bath is provided in U.S. Pat. No. 3,675,442 for obtaining potable water from moisture-laden air. A mechanical refrigeration system intermittently cools the fresh water bath. A conduit permits the fresh water in the bath to flow to and from a specially designed housing that channels a flow of moisture-laden air. Vertically aligned condenser filaments are positioned within the housing and connected to the conduit to provide condensing surfaces at a temperature below the dew point of the air in the housing. Distributing means are provided for either directing the condensed water, depending on its temperature, to the bath, or for directing the condensed water from the apparatus as output water.
The above inventions that rely upon heat convection in large structures in extraction of freshwater from the atmosphere do not relate to the present invention, which is based on processes that are performed within compact structures.
In addition, the prior art includes simple devices for extraction of potable water from humid air; such as U.S. Pat. Nos. 4,418,549 and 4,351,651 that teach the design of a device for extracting potable water from moisture-laden air at atmospheric temperature through the use of a heat exchanger at or near subsurface temperature, which is in air communication with the atmosphere for allowing atmospheric moisture-laden air to enter, pass through, cool, arrive at its dew point, allow the moisture in the air to precipitate out, and allow the air to pass outward to the atmosphere again. Suitable apparatus may be provided to restrict airflow and allow sufficient residence time of the air in the heat exchanger for sufficient precipitation. Further, filtration is provided on the air input. A movement pressure is created by a turbine on the output. The water from the system may then be collected and provided for human consumption in a conventional manner. The present invention does not use a heat exchanger for precipitation of atmospheric moisture.
Heat pipes are used in some inventions to cool a condensing surface to dew point to precipitate the water vapor from the atmosphere. An example is U.S. Pat. No. 5,553,459, which discloses an invention of a device for obtaining potable water from the ambient air, comprising (1) a compressor for compressing a refrigerant; (2) a condenser for condensing the refrigerant received from the compressor; (3) an evaporator coil for receiving at one end compressed refrigerant from the condenser and being disposed in a water tank wherein the evaporator is operable for evaporating refrigerant and thereby cooling the potable water in the water tank; (4) drip coils for condensing the potable water from the ambient air with the cooled potable water from the water tank passing through the drip coils before returning to the water tank; (5) a fan for blowing ambient air about the drip coils and the condenser; (6) a discharge device connected to the drip coil; (7) a pump for pumping water through the drip coils and the discharge device; (8) a filter and ultra-violet light source for sterilizing the potable water; and (9) a non-toxic coating is provided and disposed on the interior of the drip coil and the exterior of the evaporator, with the non-toxic coating comprising 25 to 35 percent titanium oxide.
Similarly, U.S. Pat. No. 5,517,829 teaches of a device for producing filtered drinking water. Water vapor in the atmosphere is condensed on a condenser surface, which is cooled either by a standard refrigeration system or by a thermoelectric system. Condensate water is treated by filtration and by the addition of a disinfectant, and the treated water is stored in a holding tank. Auxiliary water from a local source is treated similarly in a parallel system and stored in a second holding tank. As it is pumped from holding tank to a dispensing tap, treated water passes through a second water treatment, which filters pyrogens and other bacterial residue from the water, and removes residual disinfectant.
U.S. Pat. No. 5,301,516 discloses an improved potable water collection apparatus contained within a housing, for the collection of potable water from a dynamic airflow extending between inlet and outlet ports. A compressor is mounted within the housing to circulate a refrigerant fluid in a closed loop circulation system between the compressor, a condenser coil and a cooling coil. The condenser coil and the cooling coil are mounted in the dynamic airflow extending between the, inlet and outlet ports. A water collection pan is located beneath the cooling coils to collect condensation, which forms as water droplets on the outer surface of the cooling coils, and directs the collected water droplets into a suitable water collection container. A water filter is disposed between the collection pan and the container. A liquid level sensor stop""s the operation of the compressor when the water in the collection container reaches a desired level. A temperature and/or pressure sensing valve mounted between the condensation coils and the cooling coils is used to optimize the flow of refrigerant fluid through the closed loop system. A cleaning access member is positioned to selectively provide access to the cooling coils and the collection pan when the apparatus is not in operation. A movable panel member is selectively positioned in a closed position between the cooling coil and the condensation coil for ease of cleaning.
A device was introduced in U.S. Pat. No. 5,259,203 for extracting potable drinking water from moisture-laden atmospheric air using a refrigeration system. A compact housing contains a compressor, an evaporator unit, fan unit, condenser unit, and a reservoir, which may contain a secondary evaporator unit and condenser unit. The fan pulls a stream of atmospheric air through a filter and through the evaporator to clean and cool the air and exhausts cooled air through the condenser. The water is collected as condensation by the evaporator and directed to the reservoir through a filter system and a water seal. The reservoir may have separate compartments for holding cool or warm water. The secondary evaporator is submersed in the cool water compartment for cooling the water collected in the reservoir and the secondary condenser is submersed in the warm water compartment for heating the collected water. Operation of the system is controlled by a control module that may also contain a microprocessor for assuring maximum condensation and a removable integrated circuit program module to alter the operation for specific conditions. A humidistat may also be provided to maximize efficiency of atmospheric condensation throughout various times of day or night and in various climates.
Inventions using heat pipes to cool condensing surfaces to dew point to precipitate the water vapor from the atmosphere differ from the present invention in the use of heat pipes.
Several rearrangements were made for extracting water from water vapor-rich environment when it reaches near the saturation point. However, those situations are not limited to atmospheric moisture, but could include water vapor in gases. In U.S. Pat. No. 4,256,472, a mist filter is disclosed for extracting moisture from the humidity-laden outlet air traversing through the evaporator of an automobile or other air conditioner. The mist filter comprises a pair of corrugated screens, with the corrugation of each screen being arranged perpendicularly with the corrugations of the other adjacent screen, a pair of said screens being fastened together, and arranged contiguously with the evaporator of the air conditioner.
A droplet separator for removing drops of liquid from a gas stream is disclosed in U.S. Pat. No. 4,240,814. The separator comprises a stack of corrugated plates each of which is generally planar but has corrugations formed by alternating crests and troughs of given wavelength and amplitude. The troughs of adjacent plates register with one another to define flow passages for the gas stream extending generally in a flow direction between the inlet and outlet sides of the stack. The crests of adjacent plates contact one another between the flow passages and each of the flow passages is formed with at least two bends in the plate plane effecting direction change in the gas flowing. The corrugations are all of trapezoidal cross section.
Electrostatic and magnetic fields are used to substantially enhance water product extraction yields in a dehumidifying heat exchanger apparatus. In U.S. Pat. No. 5,056,593, dehumidifying heat exchanger apparatuses are disclosed in several variations, which may economically condense and separate a potable water product from a humid air stream. Liquid water droplets are electrostatically collected on grounded or charged heat transfer tubes in the heat exchanger apparatuses. In one variation, charged or grounded horizontally-declined heat transfer tubes with attached drainage wicks attract liquid droplets and accelerate condensing heat transfer by continuous absorption and transfer of condensate. Both cascading liquid droplets and aerosol injection of fine liquid droplets may be used to provide convenient seed nuclei for condensing attachment of water vapor molecules in other variations. Water vapor molecules may be electrostatically stabilized in a polar orientation between charged electrodes and oppositely-charged or grounded heat transfer tubes, then impelled by magnetic forces onto heat transfer surfaces as a thin condensing film. A simplified closed cycle heat transfer system is disclosed which may economically reject condensing heat to atmosphere. The heat exchanger apparatuses may operate with considerable energy economies, since substantial moisture separation may occur without any need to cool an entire air stream to below local saturation or dew point temperatures. Forms of the invention may collect potable water from humid air in water-short regions, dehumidify air in air conditioning apparatuses, separate out condensable vapor pollutants in air pollution control equipment and separate condensable vapors from gaseous fluids in chemical processes.
A water-generating device was disclosed for obtaining portable water from ambient air inside or outside a structure or dwelling in U.S. Pat. No. 5,203,989, 5,149,446 and 5,106,512. The components of the device include an air filter; a condenser for extracting water vapor in the air; an immediate temporary holding reservoir, which contains an ultraviolet light to kill existing microorganisms; a pump to transport the water through a subsequent water filter for a second exposure to ultraviolet light. At the final discharge point to the internal or external water-storage unit there may be another ultraviolet light that creates a sterile outlet from the primary system.
U.S. Pat. No. 4,255,937 reports an atmospheric water collector that collects water from the atmosphere by providing a portable cabinet in which the entire apparatus is located, needing only a source of electricity. A dehumidifier is located in an upper compartment separated by a horizontal partition from a lower compartment. In the upper compartment, two opposite walls are perforated to provide access of new moisture carrying air to circulate about the dehumidifier, and a water discharge spout is also located above the horizontal partition, but is outside the dehumidifier compartment. Water feed conduit from the dehumidifier leads to a water-collecting tank in the lower compartment, passing through a water filter on its way. A ultra-violet light bulb sterilizes the water in the tank. A water level control in the collecting tank controls the operation of the dehumidifier. A water pump controlled by a combination water discharge spout and pump switch pumps the water to the spout, up through a check valve and another filter. A complete electric refrigerator is also included with the cabinet for keeping the water cool and drinkable.
U.S. Pat. No. 5,039,407 provides a water reclamation and collection unit to collect exterior moisture in any form from the atmosphere and process such moisture converted to water to a chemical state where it is potable for humans or animals. The unit processes water to a cleansed and sanitized condition that will allow such water to be used for any purpose within any facility inhabited by people. The total unit process is designed to provide sufficient water to sustain the needs of persons in a facility without the need to use water from a well, public water distribution system or any other type surface water supply. The unit may be used for all purposes except, flushing toilets or fixtures used for depositing human waste.
None of the prior art references discloses the use of gravity to support the flow of water throughout a device for extraction of water from atmospheric humidity to produce potable water. Additionally, none of the prior art discloses the production of drinking water containing minerals adjusted to the taste and the health needs of the user, and, dispensing the potable water as hot, cold, or cold carbonated water. The prior art also fails to disclose diverting of the accumulated water into a separate filtered freshwater stream. Furthermore, none of the prior art inventions disclose means for diverting the flow of the accumulated water from the main storage tank in excess of its capacity for use or for disposal. In addition, none of the prior art inventions disclose disinfecting the water condensate in a cold storage and the production of lukewarm water.
According to the present invention, a gravity-driven system is disclosed for condensing water vapor from high temperature, high humidity ambient air through the use of: a commercial dehumidifier, means for collecting the condensate, an ultraviolet disinfecting and filtration device, a water storage device and a dispenser for dispensing a product of potable water upon demand. In a second aspect of the invention, a system is disclosed for condensation of atmospheric humidity by a variety of condensation units. Alternate water treatment provisions included ultraviolet radiation ozonation, chlorination, and the addition of fluorine and minerals to the product water. The water storage is aerated to clean the water supply, and water is dispensed as warm, cold and cold carbonated water, using small pumps in addition to gravity to assist in water flow. In a third aspect of the invention, a horizontally arranged system is disclosed to extract water from ambient air for mounting on land or sea vehicles and platforms. In a fourth aspect of the invention, specially designed condensation surfaces are disclosed to enhance water production from atmospheric air in regions of extremely high temperature and very high humidity.
It is an object of the present invention to provide an apparatus, utilizing conventional dehumidifiers for condensation of water vapor from ambient air indoors to supply freshwater and disinfected water suitable for drinking to small dwellings and homes of different sizes and living spaces, in regions of extremely high temperature and high relative humidity.
It is another object of the present invention to provide an apparatus, utilizing conventional dehumidifiers for condensation of water vapor from ambient open-air outdoors to supply freshwater and disinfected water suitable for drinking to a group of people, in regions of extremely high temperature and high relative humidity.
It is a third object of the present invention to provide a small, light weight apparatus of limited capacity to collect water vapor from hot humid ambient air, indoors or outdoors to continuously provide people with freshwater and drinking water through gravitational flow of the product water from conventional dehumidifiers.
It is a fourth object of the present invention to provide a small, light weight apparatus of limited capacity to collect water vapor from hot humid ambient air, outdoors to continuously provide people in remote areas and sparse population with freshwater and drinking water through gravitational flow of the product water and minimal electric power requirement, using a standalone power source.
It is a further object of the present invention to provide a complete integrated device for extraction of water from the atmosphere in hot and humid regions; by appropriate condensation surfaces and cooling cycles, using pump assisted water flow, to continuously provide people anywhere with freshwater and high purity potable water.
It is a still further object of the present invention to provide an apparatus for production of water from atmospheric humidity using a condensation surface optimized for maximum production of freshwater.
It is a still further object of the present invention to provide an apparatus for production of water from atmospheric humidity; to supply aerated drinking water with agreeable taste, in one or more of three states, cold, warm, or carbonated and cold.
It is a still further object of the present invention to provide an apparatus for production of water from atmospheric humidity; to supply drinking water free from microbes, bacteria, volatile organic material, harmful suspended or dissolved solids, of a quality higher than local and world standards of pure drinking water, and yet contains beneficial minerals present in typical natural water.
It is a still further object of the present invention to provide a portable apparatus to collect water vapor from ambient open air to continuously provide people with potable water upon demand whether outdoors or aboard land or seagoing vehicles.
It is yet a further object of the present invention to provide a small, lightweight mobile apparatus of limited capacity that can be transported from one place to another to collect water vapor from hot humid open air to provide people with freshwater and drinking water upon demand using pumps and controls.
It is a still further object of the present invention to provide a complete, integrated small, light weight apparatus of limited capacity to collect water vapor from indoor or outdoor ambient air to continuously provide freshwater and high purity potable water in one or more of three states hot, cold, or warm with added beneficial minerals.
It is a still further object of the present invention to provide an apparatus for extraction of atmospheric humidity wherein treatment of freshwater is accomplished by two stages of disinfection using ultraviolet radiation and two stages of filtration of suspended solids.
It is a still further object of the present invention to provide an apparatus for extraction of atmospheric humidity wherein treatment of freshwater is accomplished by ozonation and two stages of filtration of suspended solids.
It is a still farther object of the present invention to provide an apparatus for extraction of atmospheric humidity wherein treatment of freshwater is accomplished by chlorination and two stages of filtration of suspended solids.
It is a still further object of the present invention to provide an apparatus for extraction of atmospheric humidity wherein fluorine is added to the drinking water for the benefit of the consumer.
It is a still further object of the present invention to provide a mobile apparatus for extraction of atmospheric humidity to supply resorts with freshwater and drinking water upon demand.
It is a still further object of the present invention to provide a mobile apparatus for extraction of atmospheric humidity to supply freshwater and drinking water upon demand in situations of emergency.
In a first embodiment of the invention, an apparatus utilizes an adaptation of commercial indoor dehumidifiers, which are normally used to dry indoor air and direct the condensate to a drain in a container for eventual disposal. The smallest device can produces on the average no less than thirty (30) liters per day of pure water in a weather characterized by extremes of high temperature and high relative humidity day and night and all year around. The quantity of potable water is equivalent to the amount of water to be drained from a dehumidifier with the same capacity operating continuously in a hot and humid closed space. Larger capacity space dehumidifiers are commercially available and hence implementation of units of higher capacity is possible. Furthermore, dehumidifiers provide heat transfer surfaces for condensation of water vapor in the air and hence other means of vapor condensation can be used.
The drained water is disinfected, filtered, and stored for dispensing on demand. The orientation of the components is such that the product water flow is completely accomplished by gravity from collection to supply of water to the consumer.
The apparatus resembles a commercial water cooler fountain; such as those used in offices, dispensing water at ambient temperature. The height of a unit; assembled in a cabinet, is almost one and a half times the height of a standard cooler due to the location of the dehumidifier on the top of the water holding bottle. Unassembled, the unit can have different orientations as long as dispensing drinking water is convenient and the flow is maintained vertically. Lateral placement of the components on a kitchen counter or a table would require the use of water pumps, which requires additional electric power over that required for the dehumidifier.
Lower quality freshwater can be drawn for human use other than drinking by elimination of the water treatment stage, that is disinfection and possibly filtration depending on the location of the apparatus, which can be used indoors or outdoors.
Since the capacity of the freshwater storage in the water-producing system is limited, in the second embodiment of the apparatus treated freshwater is directed to fill an additional secondary closed storage tank and through drainage of excess production by gravity to an external open tank. One of the streams can be used for filling large removable water bottles for use in water coolers and the like. Excess product water may be used to fill potable water bottles by gravity for use away from the system location including the use for office coolers and water dispensers.
In the third embodiment of the invention, a bypass for untreated fresh water is incorporated to provide lower quality freshwater for different uses of water other than drinking.
Although outdoor air drying equipment is not commercially familiar; however such devices as well as indoor dehumidifiers can be used for condensing outdoor water vapor from ambient air for supply of potable water through appropriate modifications. This would facilitate the use of the water-producing device in the open air whether outside buildings or on board of transportation vehicles including land vehicles or boats and seagoing ships. This is because the size of the system is relatively small, lightweight and has small footprint. In the same time, the simple device may be equipped for continuous operation to collect water and process it to supply drinking water and/or freshwater. The system can be powered by mobile power sources.
Disinfection of product water in smaller systems can be accomplished by ultraviolet radiation emitted by small radiation sources. In larger systems, alternate disinfection and multiple filtration stages may be used. The drinking water has to be free from microbes, bacteria, volatile organic material, harmful suspended or dissolved solids, and of a quality equivalent to, or higher than local and world standards of pure drinking water. The taste of the water can be adjusted to be agreeable to the taste of the consumers by adding minerals to the product water to provide them also with the required minerals present in typical natural water.
In a second aspect of the invention, different condensation units can be used ranging from conventional refrigerant cycles to thermoelectric and thermo-acoustic refrigeration units as well as cooling condensation surfaces with cold water if a source of cold water is available. In addition, water pumps are used to assist water flow by gravity in the apparatus. In one of the embodiments of this aspect of the invention, two stages of ultraviolet disinfection and two stages of filtration are used in the water-production system. Air or oxygen is pumped in a water storage holding tank for aeration to keep the freshness of the drinking water. The drinking water stream is monitored for mineral content and a solution of natural minerals useful for enriching the potable water is added in controlled spikes to the collected condensate for taste improvement according to the desire of the user. The minerals could be added in the form of strained seawater or a solution of sea salt, rock salt or other available minerals. Before delivery of the water to the user as drinking water, the water is filtered and disinfected to assure that the potable water is free of suspended dust from the air, organic and inorganic contaminants, volatile and dissolved particulates to supply pure water of high quality for drinking through two streams one for cold water and one for warm water. Additional line may be incorporated to provide carbonated water via addition of carbon dioxide.
In an alternate embodiment of the second aspect of the invention, ozonation of the water in the holding tank replaced ultraviolet disinfection and aeration. Chlorination of drinking water and the addition of fluoride were used in a different embodiment to replace the ultraviolet disinfection and to provide additional health benefits.
In a third aspect of the invention, horizontal orientation of the components of the apparatus using pumps, air blowers, and controls allows for extraction of water from atmospheric humidity in different weather conditions and in locating the apparatus aboard land or sea vehicles. The water system can be skid mounted and placed on a trailer or a truck for supply of drinking water to small or large groups in different locations whether on temporary basis or in case of emergencies.
Increase in production capacity of water extracted from atmospheric humidity can be further achieved by design and construction of condensation surfaces for optimal water production, rather than effectiveness in drying ambient air.
FIG. 1 schematically shows a side view of a simple device for production of a limited quantity of potable water using a commercial indoor dehumidifier, after slight modifications to condensate water vapor entrained in hot humid air. The water flow is completely driven by gravity. The device may stand up as shown or may be placed on a table or a bench at the place of use inside or outside a building.
FIG. 2a schematically shows a view of the backside of a simple device for production of potable water from hot and humid air, inside or outside a building, using a modified commercial indoor dehumidifier, wherein the water flow is completely driven by gravity. The device is identical to that shown in FIG. 1 with the addition of extra capacity for increased water production and the introduction of ways to distribute the water product.
FIG. 2b is a view of the front side of the device of FIG. 2a to show collection of condensate, dispensing of product water and the flow of air through the device.
FIG. 3 is a three-dimensional graph of the rate of condensation of atmospheric water vapor per hour as function of the relative humidity and temperature in degrees Celsius.
FIG. 4 shows a side view of an embodiment of a device similar to the device of FIG. 2 wherein freshwater in excess of the capacity of the potable water tank is directed before disinfection and filtration for different uses.
FIG. 5 shows a side view of an apparatus for production of freshwater by condensation of water vapor from hot and humid air using any type of condensation equipment and diverting part of the water product for use as freshwater while converting most of the condensate to filtered and disinfected water suitable for drinking with added minerals for improvement of taste, to be drawn upon need as warm, cold or cold carbonated water with the aid of electric pumps; and the drinking water is disinfected by the use of ultraviolet lamps, while the freshness of the water product is maintained by aeration.
FIG. 6 shows a side view of an apparatus for production of freshwater by condensation of water vapor from hot and humid air using an arrangement similar to that of the apparatus in FIG. 5 with ozone as the method of water disinfection and hence no aeration is required.
FIG. 7 shows a side view of an apparatus for production of freshwater by condensation of water vapor from hot and humid air with functions similar to that of the apparatus in FIG. 6 using a different arrangement for water flow and disinfection to produce cold and hot drinking water for limited use.
FIG. 8 shows a side view of an apparatus for production of freshwater by condensation of water vapor from hot and humid air using an arrangement similar to that of the apparatus in FIG. 5 with chlorine as disinfectant and the addition of fluoride to the drinking water.
FIG. 9 shows an apparatus for production of freshwater that can be placed on a table or bench in a kitchen or a raised platform in a truck or a boat, to supply drinking water to a small group of people, by adaptation of a commercial dehumidifier for condensation of water vapor from hot and humid air and wherein pumps are used to drive the water flow in the system.
FIG. 10 shows a schematic of an implementation of a system for continuous supply of freshwater to a large group of consumers.
FIG. 11 shows the components of an apparatus for production of large quantities of drinking water, wherein a special condensation unit is used to condensate water vapor from the surrounding hot and humid air, pumps are used for water flow and ozone is used to disinfect the water before supply to the consumer.
FIG. 12 shows a high capacity version of the apparatus in FIG. 11 wherein a circular condenser is used to increase water production and minerals are added to improve the taste of the product water.